摘要
通过对高温作用后混凝土力学性能试验及扫描电镜观察,研究了温度对高温后混凝土力学性能及微观特性的影响。研究结果表明:随着温度升高,混凝土抗压强度持续降低,强度-位移曲线的峰值点呈向右向下移动趋势。就微观特性而言,原始素混凝土水泥浆体密实、无明显孔洞,水泥浆体与骨料之间黏合紧密,观察不到裂缝;400℃水泥浆体与骨料之间出现裂缝,600℃水泥浆体与骨料之间裂缝宽度显著增大,浆体中出现整体网状裂缝且局部出现较大的粉状颗粒;800℃水泥浆体与骨料之间完全脱落,浆体疏松明显。
The effect of high temperature on mechanical properties and microstructure of concrete are studied by using mechanical property tests and scanning electron microscope. Results show that the compressive strength of concrete decreases with the increase in exposure temperature, while the peak point of the strength-displacement curves downwards moves to the right. The original ce- ment paste is dense and free of obvious holes. The cement paste and aggregate are bonded tightly, and no cracks are observed. After exposure to 400℃, microcracks occur at the bonding interface of the aggregate/cement paste. After exposure to 600℃, microc- racks at the bonding interface of the aggregate/cement paste are gradually expanded into a coherent whole network crack. And some big powder particles are locally formed in the cement paste. After exposure to 800℃, the aggregate and cement paste debonds and the cement paste becomes loose.
出处
《中国农村水利水电》
北大核心
2016年第7期168-170,174,共4页
China Rural Water and Hydropower
基金
西北农林科技大学博士科研启动基金项目(2012BSJJ005)
西北农林科技大学大学生创新创业训练计划资金资助(201510712903)
高等学校基本科研义务费资助(QN2013050)
西北工业大学凝固技术国家重点实验室开放课题(SKLSP201304)
关键词
混凝土
高温
力学性能
微结构
concrete
high temperature
mechanical properties
microstructure
